000 AXNT20 KNHC 111757 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT OCT 11 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL WAVE IS ALONG 37W S OF 17N MOVING W 10 KT. A 1009 MB SFC LOW IS ALONG THE WAVE AXIS NEAR 12N37W. THIS SYSTEM CONTINUES TO SHOW SIGNS OF ORGANIZATION. A TROPICAL DEPRESSION COULD FORM DURING THE NEXT DAY OR TWO AS THE SYSTEM MOVES SLOWLY TOWARD THE WEST-NORTHWEST OR NORTHWEST. SATELLITE IMAGERY REVEALS SOME BANDING FEATURES WITH MODERATE CONVECTION MAINLY WITHIN 160 NM NW QUADRANT. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 50W FROM 14N-22N MOVING W NEAR 10 KT. VIS SAT IMAGERY INDICATES A WEAK INVERTED-V PATTERN WITH NO SIGNIFICANT CONVECTION. THE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 65W IS RELOCATED FURTHER EAST ALONG 63W BASED ON VIS SATELLITE IMAGERY AND SFC OBSERVATIONS ACROSS THE LESSER ANTILLES. A 1009 MB SFC LOW IS ALSO ADDED ALONG THE WAVE AXIS NEAR 13N. THIS SYSTEM IS MOVING SLOWLY WNW. A LARGE AREA OF CLOUDINESS WITH EMBEDDED MODERATE TO ISOLATED STRONG CONVECTION PRIMARILY OVER THE LESSER ANTILLES IS ASSOCIATED WITH THIS SLOW WESTWARD MOVING TROPICAL WAVE/LOW. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT AT THIS TIME. THE GFS COMPUTER MODEL CONTINUES TO DEVELOP A LOW PRESSURE CENTER SW OF PUERTO RICO BY TUE AND MOVES THE LOW TO THE NE ACROSS THE ISLAND INTO THE ATLANTIC OCEAN TUESDAY AND WEDNESDAY. MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE WILL SPREAD OVER THE UK/US VIRGIN ISLANDS AND PUERTO RICO TONIGHT AND SUN. THE ISLAND OF GUADELOUPE REPORTED 1.15 INCHES OF RAIN THIS MORNING FOR THE PAST 24 HOURS. A TROPICAL WAVE IS OVER NORTHERN CENTRAL AMERICA ALONG 88W/89W S OF 19N MOVING W NEAR 10 KT. THE WAVE IS GENERATING AN AREA OF SCATTERED MODERATE CONVECTION FROM 15N-19N BETWEEN 86W-89W. THIS ACTIVITY IS AFFECTING MAINLY PARTS OF BELIZE AND HONDURAS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 10N25W 12N35W 9N43W 10N61W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVES... SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 21W-27W. ...DISCUSSION... GULF OF MEXICO... HIGH PRES CENTERED OVER THE NE CONUS DOMINATES THE NORTHERN GULF WATERS PRODUCING MODERATE ELY WINDS. THIS STRONG HIGH PRES WILL BECOME CENTERED OVER THE MID ATLC STATES MON THROUGH WED KEEPING A RIDGE OVER THE GULF REGION AND INCREASING THE ELY WINDS OVER MUCH OF THE CENTRAL AND EASTERN GULF TUE AND WED. A SFC TROUGH IS OVER THE SW GULF AND RUNS FROM 24N95W TO 19N92W. SCATTERED SHOWERS ARE ASSOCIATED WITH THIS FEATURE PARTICULARLY OVER THE BAY OF CAMPECHE. A FRONTAL TROUGH EXTENDS SW FROM A 1012 LOW IN THE W ATLC NEAR 31N78W THROUGH SOUTH CENTRAL FLORIDA INTO THE EASTERN GULF NEAR 25N84W WITH NO PRECIPITATION. MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE GULF OF MEXICO. ALOFT...AN UPPER-LEVEL HIGH IS ANCHORED OVER MEXICO NEAR TAMPICO PRODUCING MODERATE TO STRONG UPPER-LEVEL NLY FLOW OVER THE ENTIRE REGION. THESE WINDS ARE ENHANCING CONVECTION ASSOCIATED WITH THE TROPICAL WAVE LOCATED OVER CENTRAL AMERICA. AN UPPER- LEVEL LOW CENTERED OFF THE COAST OF SOUTH CAROLINA NEAR 31N79W HAS A TROUGH WHICH EXTENDS ACROSS SOUTH FLORIDA AND WESTERN CUBA. MID/UPPER DRY AIR COVERS THE STATE OF FLORIDA AND THE EASTERN HALF OF THE GULF REGION. CARIBBEAN SEA... AN ACTIVE TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN PRODUCING A LARGE AREA OF CLOUDINESS AND SHOWERS. THE SAN JUAN DOPPLER RADAR DEPICTS SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED TSTMS BETWEEN THE VIRGIN ISLANDS AND THE EASTERN PORTION OF DOMINICAN REPUBLIC...INCLUDING ALSO THE REGIONAL COASTAL WATERS. THIS ACTIVITY IS AHEAD OF THE WAVE AXIS AND LIKELY ASSOCIATED WITH AN UPPER-LEVEL LOW CURRENTLY ROTATING OVER PUERTO RICO. THIS UPPER-LEVEL FEATURE IS LIMITING THE DEVELOPMENT OF THE SFC LOW LOCATED OVER THE SE CARIBBEAN...BUT AT THE SAME TIME IS HELPING TO INDUCE MORE SHOWERS AND TSTMS ACTIVITY OVER THE EASTERN CARIBBEAN...THE LESSER ANTILLES AND THE N TROPICAL ATLC DUE TO UPPER DIFFLUENCE. WEAK CYCLONIC TURNING IS SEEN IN THE CLOUD PATTERN OVER THE SW CARIBBEAN WHERE THERE ARE SCATTERED SHOWERS. A CLUSTER OF MODERATE CONVECTION IS OVER WESTERN PANAMA LIKELY RELATED WITH THE PRESENCE OF THE EPAC ITCZ. MODERATE TRADE WINDS ARE NOTED OVER THE CARIBBEAN SEA WITH E TO SE WINDS UP TO 20 KT BEHIND THE ABOVE MENTIONED TROPICAL WAVE. IN THE UPPER LEVELS.. RIDGING IS PRODUCING UPPER LEVEL NLY FLOW OVER THE W CARIBBEAN WITH THE UPPER-LEVEL TROUGH OVER WESTERN CUBA EXTENDING SOUTH INTO THE BASIN ALONG 81W. ATLANTIC OCEAN... A 1012 MB LOW IS CENTERED OFF THE COAST OF SOUTH CAROLINA NEAR 31N78W. A FRONTAL TROUGH EXTENDS SW FROM THE LOW TO CENTRAL FLORIDA NEAR LAKE OKEECHOBEE INTO THE EASTERN GULF OF MEXICO. THE UPPER-LEVEL LOW WITH THE TROUGH ACROSS FLORIDA AND CUBA PREVIOUSLY MENTIONED SUPPORTS THESE FEATURES. FURTHER EAST...SATELLITE IMAGERY SHOWS AN AREA OF SHOWERS WITH WEAK CYCLONIC TURNING NEAR 25N68W. A SFC TROUGH WILL BE ADDED TO THE 1800 UTC SFC MAP TO TAKE IN ACCOUNT THIS SYSTEM. A STATIONARY FRONT ENTERS THE AREA NEAR 31N46W THEN CONTINUES SW TO NEAR 25N56W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM SE OF FRONT AND N OF 27N. A 1022 MB HIGH IS OVER THE E ATLANTIC NEAR 32N32W PRODUCING MOSTLY FAIR WEATHER.THIS SYSTEM IS FORECAST TO REMAIN NEARLY STATIONARY DURING THE NEXT 24 HOURS. FINALLY...A 1010 MB LOW IS NE OF THE CANARY ISLANDS NEAR 31N13W. IN THE UPPER LEVELS...A TROUGH IS OVER THE W ATLANTIC JUST EAST OF THE FLORIDA PENINSULA. A SMALL UPPER LEVEL HIGH IS NEAR 24N7OW EXTENDING A RIDGE OVER THE SE BAHAMAS AND HISPANIOLA. ANOTHER UPPER-LEVEL LOW IS NEAR 31N49W. AN UPPER-LEVEL TROUGH CONNECTS THIS LOW WITH THE ONE THAT IS SPINNING OVER PUERTO RICO. AN UPPER LEVEL HIGH DOMINATES MOST OF THE TROPICS. $$ GR